US 8,896,120 B2Granted

Structures and methods for air gap integration

AssigneeInternational Business Machines Corporation

InventorsLawrence A. Clevenger, Maxime Darnon, Qinghuang Lin, Anthony D. Lisi, Satyanarayana V. Nitta

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Abstract

Methods for producing air gap-containing metal-insulator interconnect structures for VLSI and ULSI devices using a photo-patternable low k material as well as the air gap-containing interconnect structure that is formed are disclosed. More particularly, the methods described herein provide interconnect structures built in a photo-patternable low k material in which air gaps of different depths are defined by photolithography in the photo-patternable low k material. In the methods of the present invention, no etch step is required to form the air gaps. Since no etch step is required in forming the air gaps within the photo-patternable low k material, the methods disclosed in this invention provide highly reliable interconnect structures.

Claims17

Dependent claims

An interconnect structure comprising:

a cured photo-patternable low k (PPLK) material located atop a substrate, wherein said cured PPLK material is a permanent on-chip insulator and includes a plurality of conductively filled openings located therein, wherein each of said conductively filled openings of said plurality of conductively filled openings comprises a conductive material and a diffusion barrier located on sidewalls and a bottom wall of each conductive material, and wherein a topmost surface of each of said conductive material and said diffusion barrier within said conductively filled openings is co-planar with an uppermost surface of the cured PPLK material;
at least one first air gap having a first depth located within said cured PPLK material and between first preselected neighboring conductively filled openings, wherein said at least one first air gap is in direct physical contact with said diffusion barrier of said first preselected neighboring conductively filled openings;
at least one second air gap having a second depth located within said cured PPLK material and between second preselected neighboring conductively filled openings, wherein said first depth is different than said second depth, wherein said at least one second air gap is in direct physical contact with said diffusion barrier of said second preselected neighboring conductively filled openings;
and
a dielectric cap located atop the cured PPLK material as well as atop said at least one first air gap and the at least one second air gap, wherein each of said at least one first air gap and said second air gap has a bottommost surface that directly contacts a portion of said cured PPLK material which includes said plurality of conductively filled openings located therein.

2 more elements

An interconnect structure comprising:

a cured permanent on-chip photo-patternable low k material located atop a substrate, wherein the cured photo-patternable low k material is a permanent on-chip insulator and includes a plurality of conductively filled openings located therein, wherein each of said conductively filled openings of said plurality of conductively filled openings comprises a conductive material and a diffusion barrier located on sidewalls and a bottom wall of each conductive material, and wherein a topmost surface of each of said conductive material and said diffusion barrier within said conductively filled openings is co-planar with an uppermost surface of the cured PPLK material;
a plurality of first air gaps each having a first depth located within the cured photo-patternable low k material and between a first preselected set of conductively filled openings, wherein a lower portion of each of the plurality of first air gaps is connected beneath the first set of conductively filled openings and said at least one first air gap is in direct physical contact with said diffusion barrier of said first preselected neighboring conductively filled openings;
at least one second air gap having a second depth located within the cured photo-patternable low k material and between a second preselected set of conductively filled openings, wherein the first depth is different than said second depth, wherein said at least one second air gap is in direct physical contact with said diffusion barrier of said second preselected neighboring conductively filled openings;
and
a dielectric cap located atop the cured photo-patternable low k material as well as atop each of said air gaps, wherein each of said at least one first air gap and said second air gap has a bottommost surface that directly contacts a portion of said cured PPLK material which includes said plurality of conductively filled openings located therein.

2 more elements

A method of forming an air-gap containing interconnect structure comprising:

providing a photo-patternable low k material atop a substrate, said photo-patternable low k material having a plurality of conductively filled openings located therein, wherein each of said conductively filled openings of said plurality of conductively filled openings comprises a conductive material and a diffusion barrier located on sidewalls and a bottom wall of each conductive material, and wherein a topmost surface of each of said conductive material and said diffusion barrier within said conductively filled openings is co-planar with an uppermost surface of the photo-patternable low k material;
forming at least one first gap having a first depth within the photo-patternable low k material between first preselected neighboring conductively filled openings and at least one second gap having a second depth within the photo-patternable low k material between second preselected neighboring conductively filled openings, wherein the first depth is different from the second depth, and said forming the at least one first air gap and the at least one second air gap comprises exposing portions of the photo-patternable low k material to irradiation and developing the exposed portions of the photo-patternable low k material utilizing an aqueous base developer;
curing the photo-patternable low k material, wherein after said curing said topmost surface of each of said conductive material and said diffusion barrier within said conductively filled openings is co-planar with an uppermost surface of the cured photo-patternable low k material;
and
forming a dielectric cap atop the cured photo-patternable low k material and atop the at least one first and second gaps.

2 more elements

Dependencies are inferred from the claim text.

Facts

Application: 12/768,267Filed 27 Apr 2010
Published: US 2011/0260326 A127 Oct 2011
Granted: 25 Nov 2014
Term ends: Not estimatedThe source records don’t support an estimate.

Classification13 codes

H10W 20/074
Of dielectric parts thereof: of dielectric parts comprising thin functional dielectric layers, e.g. dielectric etch-stop, barrier, capping or…
H10P 14/60
Formation of materials, e.g. in the shape of layers or pillars: of insulating materials
H10P 14/6336
Using decomposition or reaction of gaseous or vapour phase compounds, i.e. chemical vapour deposition: in the presence of a plasma [PECVD]
H10P 14/6342
Deposition processes: liquid deposition, e.g. spin-coating, sol-gel techniques or spray coating